Insulative moisture vapor permeable membrane and method

ABSTRACT

An insulative moisture vapor transmission membrane with reflective barrier is provided. A method of manufacturing the membrane includes providing metallic powder and incorporating it into a liquefied polyurethane. The membrane may be incorporated into wearable garments either directly, or in a laminate form.

This application claims priority to U.S. Provisional Application No. 62/214,249 filed Sep. 4, 2015, the disclosure of which is now expressly incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates generally to insulative moisture vapor permeable membrane and method of making, and more specifically to a method and apparatus for protecting occupants from the ambient elements through an illustratively lightweight reflective membrane integrated into apparel.

BACKGROUND AND SUMMARY OF THE INVENTION

It is desirable to have protection from ambient weather conditions or elements when outdoors. Such ambient weather conditions could include wind, rain, sleet, snow, temperature, and UV rays. For example, in the case of those engaged in, or observing hunting, fishing, hiking or other outdoor athletic endeavors, it is desirable to have apparel that provides resistance to the elements and insulation that is thin and breathable but provides the same warmth as traditional thicker, bulkier, heavier insulated pieces of apparel.

Attempts have been made in the prior art to reduce the bulk of insulative apparel. For example, aluminum sheets, spray coated aluminum layers, and aluminum ink traces have been provided in apparel. However, the reduction in bulk also reduces the “breathability” or moisture vapor transmission of the apparel. Alternatively, the reduction in bulk results in a material that does not provide adequate insulation. Furthermore, these methods require additional manufacturing steps and cost in production. Thus there is a need for a material that provides insulation and resistance to ambient weather conditions while maintaining breathability.

The present disclosure may comprise one or more of the following features and combinations thereof.

The illustrative embodiments disclosed herein generally comprise insulative moisture vapor transmission membrane and methods of manufacture and incorporation into clothing.

In some embodiments, a membrane comprises a mixture of polyurethane and metallic powder wherein the metallic powder is configured to act as a radiant barrier while maintaining the moisture vapor transmission and wind resistant and water resistant capabilities provided by the polyurethane. The metallic powder may be nano-particle sized aluminum powder

In other embodiments a method of making a waterproof, water vapor permeable, reflective membrane comprises liquefying polyurethane grain; mixing aluminum powder into the liquefied polyurethane grain; and building up the membrane. The membrane may be built directly on a fabric. The membrane may be built on a substrate to form a sheet.

In other embodiments, insulative clothing is provided comprising a wearable garment means for reflecting heat so that the garment maintains moisture vapor transmission. The means for reflecting heat may include a metallic reflective powder incorporated into the polyurethane laminate.

Additional features of the present disclosure will become apparent to those skilled in the art upon consideration of illustrative embodiments exemplifying the best mode of carrying out the disclosure as presently perceived.

BRIEF DESCRIPTION OF THE DRAWINGS:

The detailed description particularly refers to the accompanying figures in which:

FIGS. 1A-1B are illustrative wearable fabrics having an insulative water vapor permeable membrane;

FIG. 2 is an illustrative method of making the insulative water vapor permeable membrane of FIG. 1.

DETAILED DESCRIPTION OF THE DRAWINGS

For the purposes of promoting an understanding of the principles of the disclosure, reference will now be made to a number of illustrative embodiments illustrated in the drawings and specific language will be used to describe the same.

A heat retaining membrane 10 is provided as a thin layer for coating a fabric 12 of an illustrative wearable article 14 in order to provide a radiant barrier, as well as water and wind resistance, and moisture vapor transmission. Illustrative membrane 10 is shown on a flexible fabric that may comprise a wearable article. It is contemplated that the membrane 10 may be incorporated into apparel such as waders, footwear, pants, hats, jackets, and other wearable articles.

Illustrative membrane 10, is a mixture including a metallic powder. When integrated into wearable articles, the resulting article is able to be washed without losing its barrier and breathable properties. Illustrative membrane 10 may be incorporated into a fabric 12 as part of a wearable garment to reflect or retain inside an interior cavity of the wearable article any heat or cold air and may reflect or retain any ambient sources of heat or cold air exterior to a cavity, where the cavity is formed between the garment and a person wearing it. Illustrative membrane 10 may be incorporated directly onto fabric FIG. 1A or take the form of a laminate attached via an adhesive 11 in FIG. 1B as described in further detail below. While acting as a reflective barrier to retain heat, the membrane also provides breathability and moisture transmission, while being waterproof. This permits the user of the clothing to be active while providing requisite climate control inside the garment,

In a method of manufacturing the illustrative membrane 200, as described in FIG. 2, polyurethane grain is liquefied 205. Metal powder, preferably aluminum powder, is added to the liquid and mixed to distribute the powder within the mixture 207. The mixture is then built up to form a breathable, heat reflective membrane 209.

In preferred embodiments, the metal powder is an aluminum powder with a particle size on the order of nanoparticles. The amount of powder added to the liquid may be any amount to provide sufficient reflection, and in a preferred embodiment, is 3-3.5% by weight. In this embodiment, the powder will provide at least 20% barrier reflection.

The mixture may be built up in a plurality of methods including building up directly on a fabric as seen in FIG. 1A. Using a process of wet-coating, the mixture may be applied to a fabric using a doctor blade to achieve a desired thickness on the fabric when it cures. In yet another process, the mixture may be built up by applying it to a stretched film such as PTFE film using a doctor blade. The sheet may then be laminated using a pair of lamination rollers to cure the mixture layer. The resulting sheet may be adhered to fabrics via an adhesive as shown in FIG. 1B. Adhesives may be moisture vapor permeable adhesives. In some instances, the sheet may be sandwiched between two fabrics using adhesive or a combination of the direct fabric layering and an adhesive and the resulting cloth laminate may be cured in an oven.

Although certain embodiments have been described and illustrated in exemplary forms with a certain degree of particularity, it is noted that the description and illustrations have been made by way of example only. Numerous changes in the details of construction, combination, and arrangement of parts and operations may be made. Accordingly, such changes are intended to be included within the scope of the disclosure, the protected scope of which is defined by the claims. 

1. A insulative membrane comprising: a mixture of polyurethane and metallic powder wherein the metallic powder is configured to act as a radiant barrier while maintaining the moisture vapor transmission and wind resistant and water resistant capabilities provided by the polyurethane.
 2. The insulative membrane of claim 1, wherein the metallic powder comprises aluminum nano-particles.
 3. The insulative membrane of claim 1, further configured to be integrated into wearable articles.
 4. Insulative clothing comprising: a wearable garment means for reflecting heat so that the garment maintains moisture vapor transmission.
 5. The insulative clothing of claim 6, wherein the means for reflecting heat comprises a metallic reflective powder incorporated into the polyurethane laminate.
 6. An insulative fabric comprising: a base fabric; a microporous film made from a mixture of polyurethane and metallic powder wherein the metallic powder provides radiant reflection and the polyurethane provides a waterproof barrier while maintaining moisture vapor transmission.
 7. The insulative fabric of claim 7, wherein the metallic powder comprises aluminum powder.
 8. A method of making a waterproof, water vapor permeable, reflective membrane comprising: liquefying polyurethane grain; mixing aluminum powder into the liquefied polyurethane grain; and building up the membrane.
 9. The method of claim 8, wherein building up the membrane comprises building it directly on a fabric.
 10. The method of claim 8, wherein building up the membrane comprises building it on a substrate to form a sheet. 